Inmunoterapia para el tratamiento del cáncer de cabeza y cuello ¿dónde estamos y hacia dónde vamos? / Immunotherapy for the treatment of head and neck cancer: where are we and where are we going?

El cáncer de cabeza y cuello comprende a todos aquellos tumores que se desarrollan en el tracto aerodigestivo superior, una de las características de éstos es su diversidad, que no es solo desde el punto de vista histológico y etiológico, sino que incluyen diversas formas de presentación, progresión y enfoques terapéuticos. Son de causa multifactorial, siendo el alcohol y el tabaco los principales factores de riesgo asociados; en los últimos años se ha relacionado a ciertos virus con potencial oncogénico con la génesis tumoral, entre ellos al Virus del Papiloma Humano, lo que ha permitido modificar el sistema de estadificación tumor primario-nodos linfáticos cancerosos-metástasis (TNM); presentándolo ahora en dos grandes grupos acorde a la Proteína supresora de tumores P16: P16+ y P16-,los cuales tienen características y manejo diferente. En vista de la heterogeneidad de la enfermedad, son diversos los tratamientos que se ha empleados para el manejo de la misma, entre ellos cirugía, radioterapia, quimioterapia e/o inmunoterapia; ésta última terapéutica, está dirigida hacia la estimulación del sistema inmune del paciente con la finalidad de generar la destrucción de las células tumorales, se realizan previo a una intervención quirúrgica para reducir el tamaño del tumor. Una forma destacable, es la del bloqueo de puntos de control inmunitarios, especialmente hacia proteínas de control inmune moduladoras de respuesta de células T, como los anti-PD-1 y los anti-CTLA-4. La inmunoterapia cada vez va tomando más protagonismo en oncología, en especial las formas de evasión de las reacciones inmunitarias por parte de las células cancerígenas(AU)

Head and neck cancer includes all those tumors that develop in the upper aerodigestive tract, one of the characteristics of these is their heterogeneity, which is not only from the histological and etiological, but also include various forms of presentation, progression and therapeutic approaches.They have a multifactorial cause, with alcohol and tobacco being the main associated risk factors, however, in recent year scertain viruses with oncogenic potential have been linked to tumor genesis, including HPV, which has made it possible tomodify the TNM staging system; now presenting it in two large groups, P16+ and P16-, which have different characteristics and management. In view of the heterogeneity of the disease, there are various treatments that have been used to manageit, including surgery, radiotherapy, chemotherapy and/ orimmunotherapy which will be determined taking into account the location and tumor extension. The latter treatment, is aimedat stimulating the patient's immune system in order to generate the destruction of tumor cells, are performed prior to a surgical intervention to reduce the size of the tumor. A remarkable therapy is that of blocking immune checkpoints, especially anti-PD-1 and anti-CTLA. Immunotherapy is becoming more and more prominent, however, there is still much to discover, so we believe that we should continue investigating the ways of evasion of immune reactions by cancer cells(AU)

The role of NFKB1/NFKBIA genetic variants in HPV infection: A cross-sectional cohort study.

Human Papillomavirus (HPV) is the most frequent etiological agent sexually transmitted. In the context of the immune response, NF-kB pathway plays an important role controlling the expression of several genes essential to cellular activity and structural and/or functional changes in components of this pathway can promote the development of several tumors. Thus, the study purpose was to evaluate the influence of NFKB1 rs28362491 and NFKBIA rs696 genetic variants on HPV infection and cervical lesions development. In this study 334 patients were recruited, of whom 48.8% (n = 163) were HPV infected, and considered our case group. HPV-DNA was detected by polymerase chain reaction (PCR) and the genetic variants were assessed in blood cells and tumor tissues paraffin embedded samples through restriction fragment length polymorphism analysis. Among women who were recruited for this study who were infected, 37.4% presented precursor lesions and 16.8% were diagnosed with cervical cancer (CC). The present study did not observe significant effects of the interaction between such genetic variants on HPV infection, nor on the development of lesions and progression to CC. Further studies will be important to investigate if under some circumstance the NFKB1 rs28362491 and NFKBIA rs696 genetic variants influence the progression of HPV-associated lesions.

Cervical cancer burden, status of implementation and challenges of cervical cancer screening in Association of Southeast Asian Nations (ASEAN) countries.

Multiple barriers impede the transformation of evidence-based research into implementation of cervical cancer screening in ASEAN countries. This review is the first of its kind to show the disease burden of cervical cancer, progress till date to implement screening and corresponding challenges, and propose tailored solutions to promote cervical cancer prevention in ASEAN. In 2020, approximately 69 000 cervical cancer cases and 38 000 deaths happened in ASEAN, and more than 44% and 63% increases on new cases and deaths are expected in 2040. Only four countries have initiated population-based cervical cancer screening programs, but the participation rate is less than 50% in some countries and even lower than 10% in Myanmar and Indonesia. Inequity and unavailability in service delivery, lack of knowledge and awareness, limited follow-up and treatment capacity, and funding sustainability affect successful scale-up of cervical cancer screening most in ASEAN. Implementing HPV detection-based primary screening, appropriate management of screen-positives, enhancing health education, integrating health services can accelerate reduction of cervical cancer burden in ASEAN. Achieving high screening coverage and high treatment compliance will help ASEAN countries remain aligned to cervical cancer elimination strategies.

The use of biomarkers and HPV genotyping to improve diagnostic accuracy in women with a transformation zone type 3.

BACKGROUND: Twenty percent of women referred to colposcopy have a type 3 transformation zone-where colposcopic assessment for high-grade dysplasia (CIN2+) is not possible. This study examines the effectiveness of HPV biomarkers and genotyping in combination with techniques that sample an endocervical TZ. METHODS: A prospective diagnostic accuracy study. Women booked for large-loop excision (LLETZ) with squamous dyskaryosis, high-risk HPV and a TZ3 were recruited. Immediately prior to LLETZ samples were collected for p16/Ki-67 dual-stained cytology, HPV genotyping and H&E, p16- and Ki-67-stained endocervical curettings. RESULTS: In women with low-grade screening (n = 64), 35.9% had CIN2+; dual-stained cytology had the greatest effect on the PPV of routine screening (76.1% vs 35.9%) and perfectly predicted the absence of CIN2+. In women with a high-grade screening result (n = 37); 75.6% had CIN2+ and dual-stained curettings improved the PPV (96.5 vs 75.6%). CONCLUSIONS: With high-grade screening and a TZ3, LLETZ appears safest as three quarters have CIN2+ . Women with low-grade screening and a TZ3 have a twofold increased risk of CIN2+ when compared to women where the TZ is visible. The use of dual-stained cytology may help identify those women who can be safely offered surveillance and those who require treatment.

Systematic review and meta-analysis of the papillomavirus prevalence in breast cancer fresh tissues.

BACKGROUND: Although widely studied, the role of HPV in the genesis of breast carcinomas remains elusive due to the diversity of results across studies, possibly caused by the wide methodological heterogeneity, some of them with inadequate methods. OBJECTIVE: To verify the association between HPV and breast cancer through the meta-analysis of studies that used the best-recognized techniques for viral detection and tissue conservation. METHODS: A systematic review and meta-analysis restricted to studies that detected HPV by PCR in fresh and frozen tissue from breast cancer were conducted to obtain greater homogeneity. PubMed, Scopus, Science Direct, Cochrane Library, and SciELO were searched until December 14, 2019. Search terms included "breast cancer" and "HPV" without language restrictions. Eleven studies were included in the meta-analysis. The pooled relative risks and 95% confidence interval (95% CI) were calculated, and heterogeneity was assessed using the I-squared (I2). RESULTS: The selected studies had very low heterogeneity (2%). There is a 2.15 times higher combined relative risk (95% CI = 1.60-2.89) of detecting HPV in breast cancer than in cancer-free breast controls with a statistically significant p-value (p < 0.0001). CONCLUSION: Our data support the association of DNA-HPV with breast carcinomas. Further studies are needed to find out which breast cancer subtypes this association is most frequent.

Association of a genetic variant in Interleukin-10 gene with increased risk and inflammation associated with cervical cancer.

BACKGROUND: Cervical-cancer is among the most commonly diagnosed cancers in women, and infection with human papillomavirus (HPV) is associated with an increased risk of cervical cancer and altered serum concentrations of inflammatory cytokines. We have explored the association between a genetic variation in the Interleukin-10 (IL-10) gene (rs1800896) and cervical cancer risk and its relationship with tissue Interferon gamma (IFN-γ), Transforming growth factor beta (TGF-ß), Tumor necrosis factor alpha (TNF-α) concentrations in women with cervical cancer. METHODS: A total of 315 women with, or without cervical cancer, were recruited into the study. DNA was extracted from cervical cells, and genotyping was undertaken using Taq-man real-time PCR. The genotype frequency and allele distribution were analyzed together with their association with pathological data. The association of the rs1800896 gene variation with tissue levels of the inflammatory cytokines was also investigated. RESULTS: Our data showed a significant association between the A allele of the rs1800896 gene variant and the presence of cervical cancer. In particular, patients with AG/AA genotypes had an increased risk of cervical cancer with an odds ratio of 1.929 (95% confidence interval [CI]: 0.879-4.23, P < 0.001) in a recessive model, compared with the GG genotype. Also, the tissue concentrations of IFN-γ, TGF-ß, and TNF-α in cervical tissues were significantly higher in women with cervical cancer (P < 0.001) and were associated with the AA genotype. CONCLUSION: We have found an association between the polymorphism rs1800896 in the IL-10 gene and an increased risk of cervical cancer as well as a higher level of tissue inflammatory cytokines. Further investigations are necessary on the value of emerging biomarkers for the risk stratification for the management of cervical cancer patients.

Percepción del riesgo de infección con virus del papiloma en jóvenes universitarios / Risk Perception about Papilloma Virus Infection in University Students

Introducción: El virus del papiloma humano es considerado la enfermedad de transmisión sexual de mayor prevalencia. El 50 por ciento de la población sexualmente activa ha tenido contacto con el virus alguna vez en su vida. Objetivo: Determinar el nivel de conocimientos y la percepción de riesgo que tiene la población universitaria de Machala acerca de la infección por virus del papiloma humano, sus aspectos generales, su transmisión y consecuencias. Métodos: Estudio transversal, cuantitativo, realizado con 239 estudiantes universitarios de uno y otro sexo. Fueron utilizadas: encuesta sobre el virus de papiloma humano en adultos, modificado con el Cuestionario de Vulnerabilidad al virus del Papiloma Humano. Resultados: Refirió que no había escuchado sobre el virus el 37,2 por ciento, principalmente estudiantes masculinos, se evidenciaron diferencias significativas (p = 0,000) en el conocimiento de la enfermedad de acuerdo al género. El 67,3 por ciento refirió nunca haber recibido charla educativa sobre el virus. La mayoría respondió adecuadamente a la forma de transmisión, que afecta a hombres como mujeres, las formas de protección, que provoca verrugas genitales, y la neoplasia del cuello uterino. Sin embargo, se encontró desconocimiento sobre la vacuna, la utilidad del Papanicolau, que esta enfermedad puede ser asintomática e incurable, y su relación con otras neoplasias. Conclusiones: La percepción de riesgo de los estudiantes fue muy baja en sentido general y más deficiente en hombres que en mujeres. En las comparaciones por sexo, se evidenció que aquellos estudiantes que recibieron charlas educativas por personal de la salud se asocian con un mejor conocimiento sobre el virus del papiloma humano(AU)

Introduction: The human papilloma virus is considered the most prevalent sexually transmitted disease. 50 percent of the sexually active population has had contact with the virus at some time in their lives. Objective: To determine the level of knowledge and risk perception of the university population of Machala about human papillomavirus infection, its general aspects, its transmission and consequences. Methods: A cross-sectional and quantitative study carried out with 239 university students of both sexes. We used a survey on human papillomavirus in adults, modified with the Human Papillomavirus Vulnerability Questionnaire. Results: 37.2 percent reported that they had not heard about the virus, mainly male students. There were significant differences (P=0.000) regarding the knowledge of the disease according to gender. 67.3 percent reported that they have never received an educational talk about the virus. Most of them responded adequately to the mode of transmission, that the virus affects men as well as women, the forms of protection, that it causes genital warts and neoplasia of the cervix. However, ignorance was found about the vaccine, the usefulness of the Pap smear test, that this disease can be asymptomatic and incurable, and its relationship with other neoplasms. Conclusions: The risk perception of the students was very low in general and more deficient in men than in women. In the comparisons by sex, it was evidenced that those students who received educational talks by the health personnel are associated with better knowledge about human papillomavirus(AU)

Tetraspanins: Host Factors in Viral Infections.

Tetraspanins are transmembrane glycoproteins that have been shown increasing interest as host factors in infectious diseases. In particular, they were implicated in the pathogenesis of both non-enveloped (human papillomavirus (HPV)) and enveloped (human immunodeficiency virus (HIV), Zika, influenza A virus, (IAV), and coronavirus) viruses through multiple stages of infection, from the initial cell membrane attachment to the syncytium formation and viral particle release. However, the mechanisms by which different tetraspanins mediate their effects vary. This review aimed to compare and contrast the role of tetraspanins in the life cycles of HPV, HIV, Zika, IAV, and coronavirus viruses, which cause the most significant health and economic burdens to society. In doing so, a better understanding of the relative contribution of tetraspanins in virus infection will allow for a more targeted approach in the treatment of these diseases.

Overview of Candida albicans and Human Papillomavirus (HPV) Infection Agents and their Biomolecular Mechanisms in Promoting Oral Cancer in Pediatric Patients.

Oral carcinoma represents one of the most common malignancies worldwide. Oral squamous cell carcinomas (OSCCs) account over 90% of all oral malignant tumors and are characterized by high mortality in the advanced stages. Early diagnosis is often a challenge for its ambiguous appearance in early stages. Mucosal infection by the human papillomavirus (HPV) is responsible for a growing number of malignancies, particularly cervical cancer and oropharyngeal carcinomas. In addition, Candida albicans (C. albicans), which is the principal fungi involved in the oral cancer development, may induce carcinogenesis through several mechanisms, mainly promoting inflammation. Medical knowledge and research on adolescent/pediatric patients' management and prevention are in continuous evolution. Besides, microbiota can play an important role in maintaining oral health and therefore all human health. The aim of this review is to evaluate epidemiological and pathophysiological characteristics of the several biochemical pathways involved during HPV and C. albicans infections in pediatric dentistry.

Host defence and persistent human papillomavirus infection.

The ability to establish long term persistent infection is a feature of human papillomaviruses. The available evidence is that this ability is a consequence of a complex local immune milieu whereby innate immune receptors and signalling pathway cascades are inhibited by HPV early proteins resulting in failure of dendritic cell maturation, antigen processing and presentation and activation of cytotoxic antigen specific T cell responses. The development of cutaneous and mucosal infection models with the mouse papillomavirus MmuPV1 and the access to multiple gene deficient strains is providing the frame work to dissect the mechanisms underlying these complex host virus interactions.

Principles of epithelial homeostasis control during persistent human papillomavirus infection and its deregulation at the cervical transformation zone.

Human papillomaviruses establish a reservoir of infection in the epithelial basal layer. To do this they limit their gene expression to avoid immune detection and modulate epithelial homeostasis pathways to inhibit the timing of basal cell delamination and differentiation to favour persistence. For low-risk Alpha papillomaviruses, which cause benign self-limiting disease in immunocompetent individuals, it appears that cell competition at the lesion edge restricts expansion. These lesions may be considered as self-regulating homeostatic structures, with epithelial cells of the hair follicles and sweat glands, which are proposed targets of the Beta and Mu papillomaviruses, showing similar restrictions to their expansion across the epithelium as a whole. In the absence of immune control, which facilitates deregulated viral gene expression, such lesions can expand, leading to problematic papillomatosis in afflicted individuals. By contrast, he high-risk Alpha HPV types can undergo deregulated viral gene expression in immunocompetent hosts at a number of body sites, including the cervical transformation zone (TZ) where they can drive the formation of neoplasia. Homeostasis at the TZ is poorly understood, but involves two adjacent epithelial cell population, one of which has the potential to stratify and to produce a multilayed squamous epithelium. This process of metaplasia involves a specialised cell type known as the reserve cell, which has for several decades been considered as the cell of origin of cervical cancer. It is becoming clear that during evolution, HPV gene products have acquired functions directly linked to their requirements to modify the normal processes of epithelial homestasis at their various sites of infection. These protein functions are beginning to provide new insight into homeostasis regulation at different body sites, and are likely to be central to our understanding of HPV epithelial tropisms.

The Not-So-Good, the Bad and the Ugly: HPV E5, E6 and E7 Oncoproteins in the Orchestration of Carcinogenesis.

Infection with HPV starts with the access of the viral particles to basal cells in the epidermis, potentially via microtraumas to the skin. The basal cells are able to keep away these pathogens in normal circumstances through a robust immune response from the host, as HPV infections are, in general, cleared within 2 to 3 weeks. However, the rare instances of persistent infection and/or in cases where the host immune system is compromised are major risk factors for the development of lesions potentially leading to malignancy. Evolutionarily, obligatory pathogens such as HPVs would not be expected to risk exposing the host to lethal cancer, as this would entail challenging their own life cycle, but infection with these viruses is highly correlated with cancer and malignancy-as in cancer of the cervix, which is almost always associated with these viruses. Despite this key associative cause and the availability of very effective vaccines against these viruses, therapeutic interventions against HPV-induced cancers are still a challenge, indicating the need for focused translational research. In this review, we will consider the key roles that the viral proteins play in driving the host cells to carcinogenesis, mainly focusing on events orchestrated by early proteins E5, E6 and E7-the not-so-good, the bad and the ugly-and discuss and summarize the major events that lead to these viruses mechanistically corrupting cellular homeostasis, giving rise to cancer and malignancy.

Genotype distribution of cervical HPV among Caribbean women in a population-based study in Martinique: The DEPIPAPUFR study.

The Caribbean ranks seventh among the world regions most affected by cervical cancer. HPV-prevalence and genotype distributions also differ from regions. Knowledge of HPV genotype profiles is important for patients care and HPV vaccination implementation. The objective of this study was to describe HPV genotype distribution and risk factors in a population-based cohort of women in Martinique. In this study, 1312 women were included and underwent cervical cancer screening with successful sample collection between 2009 and 2014. Sociodemographic and clinical variables were recorded. Cytological examination of cervical vaginal smear was performed and classified(Bethesda). Detection of HPV DNA was performed with the PapilloCheck© Kit from Greiner Bio-one. Genotypes were analyzed for18 high-risk HPV (hrHPV) and 6low-risk HPV(lrHPV) types. A total of 1075 women were included with a mean age of 49.1±10.5 years. HPV prevalence was 27.6% (297/1075) with 19.4% (209/1075) women with only hrHPV, 5.3% (57/1075) with only lrHPV. Multiple infections (hrHPV/lrHPV) were detected in 31/240 cases of hrHPV (12.9%). A total of 353 hrHPV genotypes were analyzed; the most common HPV types were HPV51 (11.0%), HPV68 (10.8%), HPV53 (9.1%) and HPV 52 (7.1%). HPV16 and HPV18 represented respectively 4.8% and 4.0% of hrHPV genotypes. Abnormal cytology was observed in 34 cases (3.2%), with 14 ASCUS (1.3%), 10 LSIL (0.9%), 5 HSIL (0.5%), 3 ASC-H (0.3%) and 2 AGC (0.2%). Fifteen (44.1%) were hrHPV and 4 (14.7%) lrHPV; 7 cases of hrPHV were in the age-group 25-34 years. Among 1041cases of normal cytology, 225 had positive hrHPV detection (21.6%). This is the first population-based study of HPV profiles in our country, and we found a high prevalence of hrHPV. The most common genotypes were HPV51, 68, 53. These results could serve for cancer vaccination strategies and HPV surveillance in Martinique.

Episome partitioning and symmetric cell divisions: Quantifying the role of random events in the persistence of HPV infections.

Human Papillomaviruses (HPV) are one of the most prevalent sexually transmitted infections (STI) and the most oncogenic viruses known to humans. The vast majority of HPV infections clear in less than 3 years, but the underlying mechanisms, especially the involvement of the immune response, are still poorly known. Building on earlier work stressing the importance of randomness in the type of cell divisions in the clearance of HPV infection, we develop a stochastic mathematical model of HPV dynamics that combines the previous aspect with an explicit description of the intracellular level. We show that the random partitioning of virus episomes upon stem cell division and the occurrence of symmetric divisions dramatically affect viral persistence. These results call for more detailed within-host studies to better understand the relative importance of stochasticity and immunity in HPV infection clearance.

The Mus musculus Papillomavirus Type 1 E7 Protein Binds to the Retinoblastoma Tumor Suppressor: Implications for Viral Pathogenesis.

The species specificity of papillomaviruses has been a significant roadblock for performing in vivo pathogenesis studies in common model organisms. The Mus musculus papillomavirus type 1 (MmuPV1) causes cutaneous papillomas that can progress to squamous cell carcinomas in laboratory mice. The papillomavirus E6 and E7 genes encode proteins that establish and maintain a cellular milieu that allows for viral genome synthesis and viral progeny synthesis in growth-arrested, terminally differentiated keratinocytes. The E6 and E7 proteins provide this activity by binding to and functionally reprogramming key cellular regulatory proteins. The MmuPV1 E7 protein lacks the canonical LXCXE motif that mediates the binding of multiple viral oncoproteins to the cellular retinoblastoma tumor suppressor protein, RB1. Our proteomic experiments, however, revealed that MmuPV1 E7 still interacts with RB1. We show that MmuPV1 E7 interacts through its C terminus with the C-terminal domain of RB1. Binding of MmuPV1 E7 to RB1 did not cause significant activation of E2F-regulated cellular genes. MmuPV1 E7 expression was shown to be essential for papilloma formation. Experimental infection of mice with MmuPV1 expressing an E7 mutant that is defective for binding to RB1 caused delayed onset, lower incidence, and smaller sizes of papillomas. Our results demonstrate that the MmuPV1 E7 gene is essential and that targeting noncanonical activities of RB1, which are independent of RB1's ability to modulate the expression of E2F-regulated genes, contribute to papillomavirus-mediated pathogenesis. IMPORTANCE Papillomavirus infections cause a variety of epithelial hyperplastic lesions, or warts. While most warts are benign, some papillomaviruses cause lesions that can progress to squamous cell carcinomas, and approximately 5% of all human cancers are caused by human papillomavirus (HPV) infections. The papillomavirus E6 and E7 proteins are thought to function to reprogram host epithelial cells to enable viral genome replication in terminally differentiated, normally growth-arrested cells. E6 and E7 lack enzymatic activities and function by interacting and functionally altering host cell regulatory proteins. Many cellular proteins that can interact with E6 and E7 have been identified, but the biological relevance of these interactions for viral pathogenesis has not been determined. This is because papillomaviruses are species specific and do not infect heterologous hosts. Here, we use a recently established mouse papillomavirus (MmuPV1) model to investigate the role of the E7 protein in viral pathogenesis. We show that MmuPV1 E7 is necessary for papilloma formation. The retinoblastoma tumor suppressor protein (RB1) is targeted by many papillomaviral E7 proteins, including cancer-associated HPVs. We show that MmuPV1 E7 can bind RB1 and that infection with a mutant MmuPV1 virus that expresses an RB1 binding-defective E7 mutant caused smaller and fewer papillomas that arise with delayed kinetics.

De-Escalating Strategies in HPV-Associated Head and Neck Squamous Cell Carcinoma.

HPV-related head and neck squamous cell carcinoma (HNSCC) has emerged as a diverse clinical and biological disease entity, mainly in young patients with oropharyngeal tumors who are nonsmokers and nondrinkers. Indeed, during the past few years, the pendulum has shifted towards a new epidemiological reality, the "HPV pandemic", where the majority of oropharyngeal squamous cell carcinomas (OPSCCs) are attributed to HPV. The oncogenic potential of the virus is associated to its capacity of integrating oncogenes E6 and E7 into the host cell, leading to the inactivation of several tumor suppressor genes, such as Rb. HPV status can affect prognosis in OPSCC, but its role as a predictive biomarker remains to be elucidated. Given the favorable prognosis associated with HPV-positive disease, the concept of de-escalation treatment strategies has been developed with the primary intent being the reduction of treatment-related long-term toxicities. In this review, we aim to depict current data regarding treatment de-escalation in HPV-associated OPSCC and discuss ongoing clinical trials.

Mouse Papillomavirus L1 and L2 Are Dispensable for Viral Infection and Persistence at Both Cutaneous and Mucosal Tissues.

Papillomavirus L1 and L2, the major and minor capsid proteins, play significant roles in viral assembly, entry, and propagation. In the current study, we investigate the impact of L1 and L2 on viral life cycle and tumor growth with a newly established mouse papillomavirus (MmuPV1) infection model. MmuPV1 L1 knockout, L2 knockout, and L1 plus L2 knockout mutant genomes (designated as L1ATGko-4m, L2ATGko, and L1-L2ATGko respectively) were generated. The mutants were examined for their ability to generate lesions in athymic nude mice. Viral activities were examined by qPCR, immunohistochemistry (IHC), in situ hybridization (ISH), and transmission electron microscopy (TEM) analyses. We demonstrated that viral DNA replication and tumor growth occurred at both cutaneous and mucosal sites infected with each of the mutants. Infections involving L1ATGko-4m, L2ATGko, and L1-L2ATGko mutant genomes generally resulted in smaller tumor sizes compared to infection with the wild type. The L1 protein was absent in L1ATGko-4m and L1-L2ATGko mutant-treated tissues, even though viral transcripts and E4 protein expression were robust. Therefore, L1 is not essential for MmuPV1-induced tumor growth, and this finding parallels our previous observations in the rabbit papillomavirus model. Very few viral particles were detected in L2ATGko mutant-infected tissues. Interestingly, the localization of L1 in lesions induced by L2ATGko was primarily cytoplasmic rather than nuclear. The findings support the hypothesis that the L2 gene influences the expression, location, transport, and assembly of the L1 protein in vivo.

Viruses Infecting the European Catfish (Silurus glanis).

In aquaculture, disease management and pathogen control are key for a successful fish farming industry. In past years, European catfish farming has been flourishing. However, devastating fish pathogens including limiting fish viruses are considered a big threat to further expanding of the industry. Even though mainly the ranavirus (Iridoviridea) and circovirus (Circoviridea) infections are considered well- described in European catfish, more other agents including herpes-, rhabdo or papillomaviruses are also observed in the tissues of catfish with or without any symptoms. The etiological role of these viruses has been unclear until now. Hence, there is a requisite for more detailed information about the latter and the development of preventive and therapeutic approaches to complete them. In this review, we summarize recent knowledge about viruses that affect the European catfish and describe their origin, distribution, molecular characterisation, and phylogenetic classification. We also highlight the knowledge gaps, which need more in-depth investigations in the future.

Human genetic and immunological dissection of papillomavirus-driven diseases: new insights into their pathogenesis.

Human papillomaviruses (HPVs) are responsible for cutaneous and mucosal lesions. Persistent HPV infection remains a leading cause of uterine cancer in women, but also of cutaneous squamous cell carcinoma in patients with epidermodysplasia verruciformis (EV), and of rare and devastating benign tumors, such as 'tree-man' syndrome. HPV infections are usually asymptomatic or benign in the general population. Severe manifestations in otherwise healthy subjects can attest to inherited immunodeficiencies. The human genetic dissection of these cases has identified critical components of the immune response to HPVs, including the non-redundant roles of keratinocyte-intrinsic immunity in controlling ß-HPVs, and of T cell-dependent adaptive immunity for controlling all HPV types. A key role of the CD28 T-cell costimulation pathway in controlling common warts due to HPVs was recently discovered. This review summarizes the state of the art in the human genetics of HPV infection, focusing on two key affected cell types: keratinocytes and T cells.